Visibility and stability of superstripes in a spin-orbit-coupled Bose-Einstein condensate

We consider a spin-$1/2$ Bose-Einstein condensate with equal Rashba and Dresselhaus spin-orbit coupling. After reviewing some relevant features of the quantum phases of the system, we present a short study on how their properties are changed by the presence of non-zero magnetic detunings and spin-asymmetric interactions. At small values of the Raman coupling and of the magnetic field the so-called stripe phase occurs, which displays both superfluidity and periodic density modulations, in analogy with supersolids. We finally review a recent proposal (Phys. Rev. A 90, 041604) to improve the visibility of the fringes, based on the space separation of the two spin components into a 2D bi-layer configuration and on the application of a $\pi/2$ Bragg pulse, and we show that this new configuration also yields a sizable increase of the stability of the stripe phase against magnetic fluctuations.Comment: 11 pages, 6 figures, peer-reviewed conference proceedings published on the EPJ-ST volume "Novel Quantum Phases and Mesoscopic Physics in Quantum Gases". The content of this article has been partially included in the review paper arXiv:1410.552

Brain and Behavior: we want you to share your data.

We at Brain and Behavior are happy, for one, that data sharing is now here

Fiscal policy and stabilization in Brazil

The theoretical basis for the"heterodox shocks"recently implemented in Argentina and Brazil is that chronic inflation is essentially inertial - the product of staggered prices and wage adjustments. The underlying assumption is that the economic process is a cooperative game. Without legal and other forms of coercion, however, individuals tend to cheat - to fix their prices above average to start with. A basic flaw of the"heterodox"stabilization programs was to assume that stabilizing the price level was a precondition for fiscal equilibrium and eventual fiscal reform - instead of the reverse. The fiscal austerity promised after stabilization was never accomplished - blocked by bureaucrats and special interest groups interested in maintaining the status quo. The challenge in these countries is to devise economic programs that could make long-term stabilization programs viable and politically acceptable.Economic Stabilization,Economic Theory&Research,Environmental Economics&Policies,National Governance,Public Sector Economics&Finance

Coulomb branches with complex singularities

We construct 4d superconformal field theories (SCFTs) whose Coulomb branches have singular complex structures. This implies, in particular, that their Coulomb branch coordinate rings are not freely generated. Our construction also gives examples of distinct SCFTs which have identical moduli space (Coulomb, Higgs, and mixed branch) geometries. These SCFTs thus provide an interesting arena in which to test the relationship between moduli space geometries and conformal field theory data. We construct these SCFTs by gauging certain discrete global symmetries of $\mathcal N=4$ superYang-Mills (sYM) theories. In the simplest cases, these discrete symmetries are outer automorphisms of the sYM gauge group, and so these theories have lagrangian descriptions as $\mathcal N=4$ sYM theories with disconnected gauge groups.Comment: 43 page

4d N\mathcal{N}=2 theories with disconnected gauge groups

In this paper we present a beautifully consistent web of evidence for the existence of interacting 4d rank-1 $\mathcal{N}=2$ SCFTs obtained from gauging discrete subgroups of global symmetries of other existing 4d rank-1 $\mathcal{N}=2$ SCFTs. The global symmetries that can be gauged involve a non-trivial combination of discrete subgroups of the $U(1)_R$, low-energy EM duality group $SL(2,\mathbb{Z})$, and the outer automorphism group of the flavor symmetry algebra, Out($F$). The theories that we construct are remarkable in many ways: (i) two of them have exceptional $F_4$ and $G_2$ flavor groups; (ii) they substantially complete the picture of the landscape of rank-1 $\mathcal{N}=2$ SCFTs as they realize all but one of the remaining consistent rank-1 Seiberg-Witten geometries that we previously constructed but were not associated to known SCFTs; and (iii) some of them have enlarged $\mathcal{N}=3$ SUSY, and have not been previously constructed. They are also examples of SCFTs which violate the Shapere-Tachikawa relation between the conformal central charges and the scaling dimension of the Coulomb branch vev. We propose a modification of the formulas computing these central charges from the topologically twisted Coulomb branch partition function which correctly compute them for discretely gauged theories.Comment: 45 pages, 3 figure